Bicycle gear changing apparatus

ABSTRACT

A bicycle gear changing apparatus is basically provided with a controller that includes memory with a plurality of pre-stored shift tables. The controller is configured to control a shifting operation of at least one of a first gear changing device and a second gear changing device based on a selected one of the pre-stored shift tables.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 13/850,550 filed on Mar. 26, 2013. The entire disclosure ofU.S. patent application Ser. No. 13/850,550 is hereby incorporatedherein by reference.

BACKGROUND

1. Field of the Invention

This invention generally relates to a bicycle gear changing apparatus.More specifically, the present invention relates to a bicycle gearchanging apparatus that controls at least one of a first gear changingdevice and a second gear changing device with a prescribed shift route.

2. Background Information

Currently, most bicycle transmissions are manually operated by a shiftoperating wire connected between a manual transmission and a manuallyoperated shift operating device mounted on the handlebar. The rideroperates the shift operating device to selectively pull or release theshift operating wire which, in turn, operates a derailleur of thetransmission in the desired manner. More recently, bicycles have beenprovided with an electric drive train for smoother and easier shifting.Electric drive trains may be operated manually or automatically. Inmanually operated electric drive trains, usually, a button or lever on ashift control device mounted to the bicycle handlebar is manipulated sothat a gear shift command is output to operate the motor for upshiftingor downshifting the bicycle transmission accordingly. In automaticallyoperated electric drive trains, the gear shift commands are generatedautomatically based on various running conditions of the bicycle.

SUMMARY

Generally, the present disclosure is directed to various features of abicycle gear changing apparatus that controls at least one of a firstgear changing device and a second gear changing device with a prescribedshift route.

In view of the state of the known technology and in accordance with oneaspect of the present invention, a bicycle gear changing apparatus isprovided that basically comprises a controller that includes memory witha plurality of pre-stored shift tables. The controller is configured tocontrol a shifting operation of at least one of a first gear changingdevice and a second gear changing device based on a selected one of thepre-stored shift tables.

In accordance with a second aspect of the present invention, the bicyclegear changing apparatus according to the first aspect further comprisesa cycle computer operatively coupled to the controller to select withwhich one of the pre-stored shift tables is used in controlling thefirst and second gear changing devices.

In accordance with a third aspect of the present invention, the bicyclegear changing apparatus according to the second aspect is configured sothat the cycling computer includes an input port configured to beattached to a computer to select the pre-stored shift tables.

In accordance with a fourth aspect of the present invention, the bicyclegear changing apparatus according to the first aspect further comprisesa first shift operating device and a second shift operating device. Thecontroller is configured to control the shifting operation of the firstgear changing device upon receiving a shift signal generated by thefirst shift operating device. The controller is configured to controlthe shifting operation of the second gear changing device upon receivinga shift signal generated by the second shift operating device.

In accordance with a fifth aspect of the present invention, the bicyclegear changing apparatus according to the fourth aspect is configured sothat the pre-stored shift tables comprise a first prescribed shift routeand a second prescribed shift route. The controller is configured toactuate the first gear changing device in accordance with the firstprescribed shift route upon receiving the shift signal generated by thefirst shift operating device. The controller is configured to actuatethe second gear changing device in accordance with the second prescribedshift route upon receiving a shift signal generated by the second shiftoperating device.

In accordance with a sixth aspect of the present invention, the bicyclegear changing apparatus according to the fifth aspect is configured sothat the first prescribed shift route includes at least onesynchro-shift point, and the second prescribed shift route includes atleast one synchro-shift point.

In accordance with a seventh aspect of the present invention, thebicycle gear changing apparatus according to the sixth aspect isconfigured so that the controller is configured to operate both thefirst gear changing device and the second gear changing device at thesynchro-shift point in response to receiving the first shift signal.

In accordance with an eighth aspect of the present invention, thebicycle gear changing apparatus according to the fifth aspect isconfigured so that the pre-stored shift table comprises further a thirdprescribed shift route and a fourth prescribed shift route.

In accordance with a ninth aspect of the present invention, the bicyclegear changing apparatus according to the eighth aspect is configured sothat the first shift operating device comprises a first electricalswitch and a second electrical switch, and the second shift operatingdevice comprises a third electrical switch and a fourth electricalswitch.

In accordance with a tenth aspect of the present invention, the bicyclegear changing apparatus according to the ninth aspect is configured sothat the controller is configured to operate the first gear changingdevice and the second gear changing device in accordance with the firstprescribed shift route in response to receiving shift signals from thefirst electrical switch. The controller is configured to operate thefirst gear changing device and the second gear changing device inaccordance with the second prescribed shift route in response toreceiving shift signals from the third electrical switch. The controlleris configured to operate the first gear changing device and the secondgear changing device in accordance with the third prescribed shift routein response to receiving shift signals from the second electricalswitch. The controller is configured to operate the first gear changingdevice and the second gear changing device in accordance with the fourthprescribed shift route in response to receiving shift signals from thefourth electrical switch.

Other objects, features, aspects and advantages of the disclosed bicyclegear changing apparatus will become apparent to those skilled in thebicycle field from the following detailed description, which, taken inconjunction with the annexed drawings, discloses preferred embodimentsof the bicycle gear changing apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the attached drawings which form a part of thisoriginal disclosure:

FIG. 1 is a side elevational view of a bicycle that is equipped with abicycle gear changing apparatus in accordance with one embodiment;

FIG. 2 is a side elevational view of the a handlebar area of the bicycleshowing a road bicycle control (brake/shift) device and a cyclingcomputer coupled to a drop type handlebar of the bicycle illustrated inFIG. 1;

FIG. 3 is a schematic block diagram showing an overall configuration ofan electric bicycle shift system including the bicycle gear changingapparatus in accordance with the embodiment illustrated in FIGS. 1 and2;

FIG. 4 is a first synchro-shift gear shifting table for a bicycle shiftsystem having three front chainwheels and ten rear sprockets;

FIG. 5 is a second synchro-shift gear shifting table for a bicycle shiftsystem having three front chainwheels and ten rear sprockets; and

FIG. 6 is a third synchro-shift gear shifting table for a bicycle shiftsystem having two front chainwheels and ten rear sprockets.

DETAILED DESCRIPTION OF EMBODIMENTS

Selected embodiments will now be explained with reference to thedrawings. It will be apparent to those skilled in the bicycle field fromthis disclosure that the following descriptions of the embodiments areprovided for illustration only and not for the purpose of limiting theinvention as defined by the appended claims and their equivalents.

Referring initially to FIG. 1, a bicycle 10 is illustrated that isequipped with a bicycle gear changing apparatus 12 in accordance with afirst embodiment. While the bicycle 10 is illustrated as a road bike,the bicycle gear changing apparatus 12 is not limited to use with a roadbike. For example, this invention can also be applied to mountain bikesor any type of bicycle. As seen in FIGS. 1 to 3, the bicycle gearchanging apparatus 12 is a part of an electric bicycle shift system. Thebicycle gear changing apparatus 12 includes a first shift operatingdevice or shifter 16 and a second shift operating device or shifter 18.The first and second shift operating devices 16 and 18 are examples ofan upshifting input and/or a downshifting input of the bicycle gearchanging apparatus 12 as explained below. The bicycle gear changingapparatus 12 also includes a signal controller 20 for changing gears ofthe bicycle 10 in response to operation of the first shift operatingdevice or shifter 16 and a second shift operating device or shifter 18.The signal controller 20 includes a microcomputer 21. The bicycle gearchanging apparatus 12 further includes a first gear changing device 22,a second gear changing device 23 and a cycling computer 24. An electric(motorized) rear derailleur corresponds to a first gear changing device22, while an electric (motorized) front derailleur that corresponds tothe second gear changing device 23.

The microcomputer 21 having a processor 21 a and memory 21 b forprocessing the various signals from the various sensors and componentsof the bicycle gear changing apparatus 12. The signal controller 20 alsoincludes a shift control program that controls the movement of the gearchanging devices 22 and 23 as discussed below. The shift control programcan be stored in the memory 21 b, which includes a ROM (Read OnlyMemory) device and a RAM (Random Access Memory) device. While the signalcontroller 20 is electrically connected to the other parts of thebicycle gear changing apparatus 12 as schematically illustrated in FIG.3, it will be apparent from this disclosure that wireless communicationmay be used to operatively couple the signal controller 20 to otherparts of the bicycle gear changing apparatus 12 for receiving data. Thesignal controller 20 interprets and executes instructions (data, signalsand commands) of the various programs and hardware to direct theoperation of the bicycle gear changing apparatus 12. While the signalcontroller 20 is illustrated as a single separate unit, the signalcontroller 20 could be part of another component or could be a part ofseveral components (e.g., multiple controllers located in differentparts).

In the illustrated embodiment, the signal controller 20 is provided witha mode button 20 a for the rider or other users to select either themanual shifting mode, which includes both a synchro-shifting mode and anon-synchro-shifting mode, or the automatic shifting mode, whichincludes both a synchro-shifting mode and a non-synchro-shifting mode.Alternatively, the operating mode of the bicycle gear changing apparatus12 can be selected in other ways such as by using the cycling computer24 and/or operating buttons on one of the first and second shiftoperating devices 16 and 18. Preferably various parameters for thebicycle gear changing apparatus 12 can be changed from a default settingby the user to provide a customized the shifting routes. The variousfeatures of the bicycle gear changing apparatus 12 can also be customizeby attaching a personal computer to the bicycle gear changing apparatus12 via a communication port 20 b.

Basically, in order to shift gears in the manual shifting mode, thefirst and second shift operating devices 16 and 18 are selected andoperated by the rider to output control signals to the signal controller20 which in turn outputs shift signals to operate the first and secondgear changing devices 22 and 23 to move a chain 26 laterally withrespect to a bicycle frame 27. In the automatic shifting mode, thesignal controller 20 controls the first and second gear changing devices22 and 23 based on one or more control signals from one or more runningcondition sensors.

Preferably, the signal controller 20 is configured to output control(shift) signals for performing a synchro-shift during both the manualshifting mode and the automatic shifting mode. Of course, the manualshifting mode and the automatic shifting mode can also be set withoutthe synchro-shift feature. As used herein, the terms “synchro-shift” and“synchro-shifting” refer to a shift in which both the rear and frontgear shifting devices (e.g., the first and second gear changing devices22 and 23) are shifted nearly simultaneously to attain a target gearratio in response to operation of a single shift operating member (e.g.,first or second shift operating devices 16 or 18) or a predeterminedrunning condition occurring.

The term “single shift operating member” as used herein referred to ashift operating member that includes an upshift switch and a downshiftswitch. However, the term “single shift operating member” as used hereinis not limited to a single shifter unit as illustrated in FIGS. 1 and 2.For example, the electrical switches SW1 and SW2 of the first shiftoperating device 16 may be disposed such that the electrical switchesSW1 and SW2 are apart from each other (e.g. the electrical switch SW1can be disposed on the right of the handlebar, while the electricalswitches SW2 is disposed on the left of the handlebar). Similarly, theelectrical switches SW3 and SW4 of the second shift operating device 18may be disposed such that the electrical switches SW3 and SW4 are apartfrom each other (e.g. the electrical switch SW3 can be disposed on theright of the handlebar, the electrical switch SW4 can be disposed on theleft of the handlebar).

In manual synchro-shifting mode, only one of the first and second shiftoperating devices 16 and 18 can be used to perform the synchro-shift,and the other the first and second shift operating devices 16 and 18 canonly be used to perform individually shifting similar to the manualnon-synchro shift mode. Thus, the one of the first and second shiftoperating devices 16 and 18 that performs synchro-shifting is referredto as a synchro-shift operating device. On the other hand, the other oneof the first and second shift operating devices 16 and 18 that performsnon-synchro-shifting is referred to as a non-synchro-shift operatingdevice.

In the manual non-synchro-shifting mode, the rider operates the firstand second shift operating devices 16 and 18 to output control signalsto the signal controller 20 which in turn outputs shift signals toindividually operate either the first gear changing device 22 or thesecond gear changing device 23.

In the illustrated embodiment, as illustrated in FIG. 3, a crankrotational speed sensor 28 and a wheel rotational speed sensor 29 areprovided for providing data to the signal controller 20 forautomatically controlling the shifting of the derailleurs 22 and 23. Forexample, based on the detection signals from the crank rotational speedsensor 28 and the wheel rotational speed sensor 29, the signalcontroller 20 outputs control signals to shift the derailleurs 22 and 23to attain a target gear ratio so that the cadence is maintained atapproximately 60-70 RPM, which is a comfortable value for an ordinaryperson cruising on a bicycle. This type of automatic shifting as well asother types of automatic shifting can be performed by the signalcontroller 20. Since conventional automatic shifting can be used, thedetails of the automatic shifting mode will not be discussed in furtherdetail herein.

As illustrated in FIGS. 1 and 2, the first and second shift operatingdevices 16 and 18 are brake and shift operating devices in which thefirst shift operating device 16 is fixedly mounted on the right-handside of the handlebar and the second operating device 18 is fixedlymounted on the left-hand side of the handlebar. In particular, the firstshift operating device 16 is operatively connected to the first gearchanging device 22 and a rear brake 30, while the second shift operatingdevice 18 is operatively connected to the second gear changing device 23and a front brake 31. In the illustrated embodiment, the first andsecond shift operating devices 16 and 18 are mechanically connected tothe rear and front brakes 30 and 31, respectively, using conventionalBowden-type brake cables. In the illustrated embodiment, the first andsecond shift operating devices 16 and 18 are electrically connected tothe signal controller 20 by first and second electrical cables 32 and33. Alternatively, the second gear changing device 23 and the frontbrake 31 can be connected to the first shift operating device 16, andthe first gear changing device 22 and the rear brake 30 can be connectedto the second operating device 18.

As illustrated in FIGS. 2 and 3, the first and second electrical cables32 and 33 output shift signals or commands to the signal controller 20for controlling the first and second gear changing devices 22 and 23,respectively. The first and second shift operating devices 16 and 18also receive electrical power from a power supply or battery 34 (seeFIG. 3). In particular, an electrical harness 35 is provided between thesignal controller 20 and the power supply 34 such that electrical poweris supplied to the signal controller 20, which in turn supplieselectrical power to the first and second shift operating devices 16 and18 via the first and second electrical cables 32 and 33, respectively.The electrical harness 35 transmits shift signals (FSS, RSS) andposition signals for the shifting devices (DATA) between the signalcontroller 20 and the first and second gear changing devices 22 and 23.The cables 32 and 33 and the electrical harness 35 may be replaced by acable which includes only two conductor cables. In this case, PLC (PowerLine communication) circuit boards may be included in the signalcontroller 20 and the first and second gear changing devices 22 and 23.

As illustrated in FIG. 2, the first shift operating device 16 isattached the curved portion of the handlebar, which is a drop-downhandlebar in the illustrated embodiment. The second operating device 18is a mirror image of the first shift operating device 16 and includesall of the features of the first shift operating device 16 discussedherein. Thus, the second operating device 18 will not be discussed indetail herein. Of course, it will be apparent from this disclosure thatother types of electric shifters can be used as needed and/or desiredinstead of the type illustrated herein.

Basically, the first shift operating device 16 includes a base member 40fixedly mounted on the right-hand side of the handlebar in aconventional manner such as a band clamp as illustrated. A brake lever43 is pivotally mounted to the base member 40 for operating the rearbrake 30 in a conventional manner. The brake lever 43 has a pair ofpivotally mounted shift operating members 44 and 45. The shift operatingmembers 44 and 45 are pushed toward a center plane of the bicycle todepress electrical switches SW1 and SW2, respectively. A more detaileddiscussion of the shift operating members 44 and 45 and the electricalswitches SW1 and SW2 can be found in U.S. Pat. No. 7,854,180 (assignedto Shimano Inc.). The shift operating members 44 and 45 are examples ofupshifting inputs and/or downshifting inputs of the bicycle gearchanging apparatus 12. The second shift operating device 18 is a mirrorimage of the first shift operating device 16, and thus, has a pair ofpivotally mounted shift operating members that operates the switches SW3and SW4.

While the shift operating members 44 and 45 and the electrical switchesSW1 and SW2 of the illustrated embodiment are constructed as shown inU.S. Pat. No. 7,854,180, the first and second shift operating devices 16and 18 are not limited to that particular construction. In fact, thefirst and second shift operating devices 16 and 18 can be replaced withmechanical shifters such as disclosed in U.S. Pat. No. 5,970,816, whichhas a manual synchro-shift system.

As mentioned above, the controller 20 is configured to set at least asynchro-shifting mode and a non-synchro-shifting mode. Hereinafter,operation of the electrical switch SW1 outputs first signals whenoperated, the electrical switch SW2 outputs second signals whenoperated, the electrical switch SW3 outputs third signals when operatedand the electrical switch SW4 outputs fourth signals when operated.While the controller 20 is set to the non-synchro-shifting mode, thecontroller 20 only controls one of the first and second gear changingdevices 22 and 23 in response to receiving the first signals and thethird signals and only controls the other of the first and second gearchanging devices 22 and 23 in response to receiving the second signalsand the fourth signals. Thus, non-synchro-shifting mode, in operation ofthe shift operating member 44 normally causes the first gear changingdevice 22 to perform a downshift operation such that the chain 26 movesto a larger one of the rear sprockets 46, while operation of the shiftoperating member 45 normally causes the first gear changing device 22 toperform an upshift operation such that the chain 26 moves to a smallerone of the rear sprockets 46. The second shift operating device 18, innon-synchro-shifting mode, operates the second gear changing device 23in a similar manner. However, the controller 20 is configured to set asynchro-shifting mode in which the controller 20 operates both the firstand second gear changing devices 22 and 23 at a synchro-shift point inaccordance with the first prescribed shift route in response toreceiving the first shift signals. However, in the synchro-shiftingmode, operation of the shift operating member 44 may cause the firstgear changing device 22 to perform a downshift operation, whileoperation of the shift operating member 45 may cause the first gearchanging device 22 to perform an upshift operation.

Referring to FIG. 3, the basic construction of the first gear changingdevice 22 will now be discussed. The first gear changing device 22 isbasically a conventional electric derailleur that includes a rearcontrol unit 22 a (controller), a motor drive unit 22 b, a positionsensor 22 c and a motor 22 e. The rear control unit 22 a, the motordrive unit 22 b and the position sensor 22 c form the rear actuatingunit. The rear control unit 22 a is configured and arranged to controlthe motor drive unit 22 b in response to a shift control signal fromoperation of one of the shift switches SW1 and SW2 of the first shiftoperating device 16. The motor 22 e is configured and arranged to drivea chain cage of the first gear changing device 22. The motor drive unit22 b is configured and arranged to drive the motor 22 e. The positionsensor 22 c is configured and arranged to sense the gearshift positionof the rear gear shifting device 22. The position sensor 22 cconstitutes one example of a transmission state determining component ofthe bicycle gear changing apparatus 12. One example of an electric rearderailleur having a position sensor (i.e., a transmission statedetermining component) is disclosed in U.S. Pat. No. 8,137,223 (assignedto Shimano Inc.). While a potentiometer can be used for the positionsensor 22 c such as disclosed in U.S. Pat. No. 8,137,223, the positionsensor 22 c is not limited to such a construction.

Referring back to FIG. 1, the bicycle 10 has a plurality of rearsprockets 46 for selectively receiving a drive force from the chain 26.Operation of the motor 22 e of the first gear changing device 22 movesthe chain 26 between the rear sprockets 46 to change rear gear stages.While the bicycle 10 is illustrated with only nine of the rear sprockets46, the bicycle 10 can be provided with fewer or more rear sprockets 46.

Referring back to FIG. 3, the basic construction of the second gearchanging device 23 will now be discussed. The second gear changingdevice 23 is basically a conventional electric derailleur that includesa front control unit 23 a (controller), a motor drive unit 23 b, aposition sensor 23 c and a motor 23 e. The front control unit 23 a, themotor drive unit 23 b and the position sensor 23 c form the frontactuating unit. The front control unit 23 a is configured and arrangedto control the motor drive unit 23 b in response to a shift controlsignal from operation of one of the shift switches SW3 and SW4 of thesecond shift operating device 18. The motor 23 e is configured andarranged to drive a chain cage of the second gear changing device 23.The motor drive unit 23 b is configured and arranged to drive the motor23 e. The position sensor 23 c is configured and arranged to sense thegearshift position of the front gear shifting device 23. The positionsensor 23 c constitutes one example of a transmission state determiningcomponent of the bicycle gear changing apparatus 12. One example of anelectric front derailleur having a position sensor (i.e., a transmissionstate determining component) is disclosed in U.S. Pat. No. 7,306,531(assigned to Shimano Inc.). While a potentiometer can be used for theposition sensor 23 c such as disclosed in U.S. Pat. No. 7,306,531, theposition sensor 23 c is not limited to such a construction.

Referring back to FIG. 1, the bicycle 10 has a plurality frontchainwheels 47 for transmitting a pedaling (drive) force to the chain26. Operation of the motor 23 e of the second gear changing device 23moves the chain 26 between the front chainwheels 47 to change front gearstages. While the bicycle 10 is illustrated with only three of the frontchainwheels 47, the bicycle 10 can be provided with two frontchainwheels or more than three front chainwheels.

The cycling computer 24 includes a microprocessor, memory and otherconventional structures of a conventional cycling computer. Sincecycling computers are conventional devices that are well known, thecycling computer 24 will not be discussed and/or illustrated herein,except as modified to accommodate the bicycle gear changing apparatus12. In particular, the cycling computer 24 is electrically connected tothe signal controller 20 by a cable 48 to receive various data fromother components of the bicycle gear changing apparatus 12. The cable48, can also optionally supply power to the cycling computer 24 asillustrated in FIG. 3. Alternatively, the cycling computer 24 can haveits own power supply (e.g., a replaceable battery).

As illustrated in FIGS. 1 to 3, the cycling computer 24 is a part of thebicycle gear changing apparatus 12. However, the various functions ofthe cycling computer 24 can be integrated into one or both of the firstand second shift operating devices 16 and 18 and/or the signalcontroller 20.

The cycling computer 24 has a display 49 for displaying gear positions,speed, traveled distance and other information to the rider as in thecase of most cycling computers. Also in the illustrated embodiment, thecycling computer 24 further includes an input port 50 that is acommunication port such as a USB port for attaching a computer to updatesoftware and/or modify various operating parameters of the bicycle gearchanging apparatus 12.

In the illustrated embodiment of FIG. 4, the gear shift mechanism (e.g.,the first and second gear changing devices 22 and 23) of the bicycle hasa plurality of speed stages (e.g. thirty speed stages without thesynchro-shift feature and twenty one speed stages with the synchro-shiftfeature). A high gear ratio refers to a higher bicycle speed perrotation of the crank arms, while a low gear ratio refers to a lowerbicycle speed per rotation of the crank arms. In the synchro-shiftoperations illustrated in FIG. 4, a single gear shift operation occursbetween the front chainwheels 47 and a double gear shift operationoccurs in the rear sprockets 46.

The bicycle transmission of FIG. 1 has a total of thirty speed stageswhile the synchro-shift feature is not in use. However, while thesynchro-shift feature is in use, the bicycle transmission of FIG. 1 hasa total of only twenty-one speed stages as illustrated in FIG. 4. In theexample of FIG. 4, the bicycle transmission of FIG. 1 includes at leastone synchro-shift point, which includes the fifth speed stage (i.e.,counting from the lowest gear ratio to the highest gear ratio along thesynchro-upshifting route). However, the bicycle transmission is notlimited to a single synchro-shift point bicycle transmission. Thelocations and numbers of synchro-shift points will depend on theparticular gear ratios that can be attained in the particular bicycletransmission. In other words, the tooth count can be changed for therear sprockets and the front chainwheels to change the gear ratios,which can be attained such that more or less rear sprockets and/or frontchainwheels can be changed for increasing or decreasing the attainablenumber of speed stages.

For example, FIG. 4 illustrates a shift table for a bicycle transmissionwith ten rear sprockets, three front chainwheels, and a synchro-shiftoccurring at the shift between the fifth and the sixth speed stages. Inthis case, when the rider operates only the upshift switch of thesynchro-shift operating device, a synchro-shift route is followed toincrease gear ratio in order from the first gear stage having a gearratio of 0.67 (CS: thirty-six teeth and FC: twenty-four teeth). In thiscase the gear ratios are changed with the upshift switch of thesynchro-shift operating device as follow: 0.67 (CS: 1st stage and FC:Low stage)→0.75 (CS: 2nd stage and FC: Low stage)→0.86 (CS: 3rd stageand FC: Low stage)→1.00 (CS: 4th stage and FC: Low stage)→1.14 (CS: 5thstage and FC: Low stage)→1.33 (CS: 4th stage and FC: Mid stage)→1.52(CS: 5th stage and FC: Mid stage)→1.68 (CS: 6th stage and FC: Midstage)→1.88 (CS: 7th stage and FC: Mid stage)→2.21 (CS: 6th stage andFC: Top stage)→2.47 (CS: 7th stage and FC: Top stage)→2.80 (CS: 8thstage and FC: Top stage)→3.23 (CS: 9th stage and FC: Top stage)→3.82(CS: 10th stage and FC: Top stage). When the rider operates onlydownshift switch of the synchro-shift operating device, a synchro-shiftroute is followed to decrease the gear ratio in order from last gearstage (CS: eleven teeth and FC: forty-two teeth). In this case the gearratios are changed with the downshift switch of the synchro-shiftoperating device as follow: 3.82 (CS: 10th stage and FC: Top stage)→3.23(CS: 9th stage and FC: Top stage)→2.80 (CS: 8th stage and FC: Topstage)→2.47 (CS: 7th stage and FC: Top stage)→2.21 (CS: 6th stage andFC: Top stage)→2.00 (CS: 5th stage and FC: Top stage)→1.75 (CS: 4thstage and FC: Top stage)→1.50 (CS: 3rd stage and FC: Top stage)→1.31(CS: 2nd stage and FC: Top stage)→1.14 (CS: 3rd stage and FC: Midstage)→1.00 (CS: 2nd stage and FC: Mid stage)→0.89 (CS: 1st stage andFC: Mid stage)→0.75 (CS: 2nd stage and FC: Low stage)→0.67 (CS: 1ststage and FC: Low stage).

Even while in the manual synchro-shifting mode, the non-synchro-shiftoperating device can be operated to perform an individual shift in thesame way as in the manual non-synchro shift mode. For example, inaccordance with the shift table of FIG. 4, when the present shift stagecorresponds to the 3rd stage of the rear stages (CS) and the Low stageof the front stages (FC) and the rider operates the upshift switch ofthe non-synchro-shift operating device, then the front stage (FC) ischanged from the Low stage to the Mid stage with the 3rd stage of thepresent rear stage (CS) remaining engaged. At this point (CS: 3rd stageand FC: Mid stage), when the rider operates the upshift switch of thesynchro-shift operating device, the rear stage (CS) is changed from the3rd stage of the rear stages (CS) to the 4th stage of the rear stages(CS) with the Mid stage of the present front chainwheel (FC) remainingengaged.

FIGS. 4, 5 and 6 are examples of prestored shift tables for use while inthe synchro-shifting mode. The prestored shift tables are stored in thememory 21 b such that the controller 20 operates the first gear changingdevice 22 and the second gear changing device 23 in response to signalsfrom the electrical switches SW1, SW2, SW3 and SW4. In particular, thecontroller 20 is configured to be operatively coupled to a first input,such as one of the electrical switches SW1, SW2, SW3 and SW4 (e.g., theelectrical switch SW1), to receive first shift signals. The controller20 outputs control signals to control at least one of the first gearchanging device 22 and the second gear changing device 23 in accordancewith a first prescribed shift route of one of the prestored shift tablesin response to receiving the first shift signals. The controller 20 isconfigured to be operatively coupled to a second input, such as one ofthe electrical switches SW1, SW2, SW3 and SW4 (e.g., the electricalswitch SW2), to receive second shift signals. Also the controller 20outputs control signals to control at least one of the first and secondgear changing devices 22 and 23 in accordance with a second prescribedshift route of one of the prestored shift tables, wherein the secondprescribed shift route is different from the first prescribed shiftroute in response to receiving the second shift signals. In other words,the controller 20 outputs control signals to selectively control thefirst and second gear changing devices 22 and 23 in response toreceiving the second shift signals. Of course, it will be apparent fromthis disclosure that additional prestored shift tables can be stored inthe memory 21 b for operating the first and second gear changing devices22 and 23 in response to signals from the electrical switches SW1, SW2,SW3 and SW4.

Preferably, the controller 20 is further configured to be operativelycoupled to a third input, such as one of the electrical switches SW,SW2, SW3 and SW4 (e.g., the electrical switch SW3) to receive thirdshift signals. The controller 20 outputs control signals to control atleast one of the first and second gear changing devices 22 and 23 inaccordance with a third prescribed shift route in response to receivingthe third shift signals.

Preferably, the controller 20 is further configured to be operativelycoupled to a fourth input, such as one of the electrical switches SW1,SW2, SW3 and SW4 (e.g., the electrical switch SW4) to receive fourthshift signals. The controller 20 outputs control signals to control theat least one of the first and second gear changing devices 22 and 23 inaccordance with a fourth prescribed shift route that is different fromthe third prescribed shift route in response to receiving the fourthshift signals.

In the synchro-shifting mode, the controller 20 can be set by the userto use the switches SW1 and SW2 of the first shift operating device 16to operate the first and second gear changing devices 22 and 23 inaccordance with the synchro-shifting routes that are prestored in theshifting table, and to use the switches SW3 and SW4 of the second shiftoperating device 18 to operate one of the first and second gear changingdevices 22 and 23 in the non-synchro-shifting routes. In other words,with the first shift operating device 16, one of the switches SW1 andSW2 performs upshifting along the synchro-upshift route and the other ofthe switches SW1 and SW2 performs downshifting along thesynchro-downshift route. With the second shift operating device 18, oneof the switches SW3 and SW4 performs upshifting of only one of the firstand second gear changing devices 22 and 23, and the other of theswitches SW3 and SW4 performs downshifting of the same one of the firstand second gear changing devices 22 and 23.

Alternatively, in the synchro-shifting mode, the controller 20 can beset by the user to use one of the switches SW1 and SW2 of the firstshift operating device 16 to perform either upshifting or downshiftingalong the corresponding synchro-shift route and to use one of theswitches SW3 and SW4 of the second shift operating device 18 to performthe other of either upshifting or downshifting along the correspondingsynchro-shift route. The remaining two of the switches SW1, SW2, SW3 andSW4 are used to operate one of the one of the first and second gearchanging devices 22 and 23 in the non-synchro-shifting routes.

The controller 20 is configured to set a synchro-shifting mode in whichthe controller 20 operates both the first and second gear changingdevices 22 and 23 at a synchro-shift point in accordance with the firstprescribed shift route in response to receiving the first shift signals.

Referring to FIG. 4, this prestored shift table has prescribed shiftroutes indicated by the broken arrows with synchro-shift points beingcircled. The synchro-shift point is determined by a pair of gear ratiosor a pair of the front shift stages and rear shift stages which occursbefore and after the shift. In this embodiment, the synchro-pointsinclude a plurality of synchro-upshift shift points and a plurality ofsynchro-downshift points. The synchro-shift point is determined by apair of gear ratios or a pair of the front shift stages and the rearshift stages which occurs before and after the shift. In thisembodiment, the synchro-shift point includes a synchro-upshift point anda synchro-downshift point. In FIG. 4, the synchro-upshift pointsincludes a pair of gear ratios 1.14 (i.e., where the pair is the frontshift stage is the Low stage and the rear shift stage is the 5th stage)and 1.33 (i.e., where the pair is the front shift stage is the Mid stageand the rear shift stage is the 4th stage), and a pair of gear ratios1.88 (i.e., where the pair is the front shift stage is the Mid stage andthe rear shift stage is the 7th stage) and 2.21 (i.e., where the pair isthe front shift stage is the Top stage and the rear shift stage is the6th stage). In FIG. 4, the synchro-downshift points includes a pair ofgear ratios 1.31 (i.e., where the pair is the front shift stage is theTop stage and the rear shift stage is the 2nd stage) and 1.14 (i.e.,where the pair is the front shift stage is the Mid stage and the rearshift stage is the 3rd stage), and a pair of gear ratios 0.89 (i.e.,where the pair is the front shift stage is the Mid stage and the rearshift stage is the 1st stage) and 0.75 (i.e., where the pair is thefront shift stage is the Low stage and the rear shift stage is the 2ndstage).

The prescribed shift routes of the prestored shift table of FIG. 4 areused while the controller 20 is in a synchro-shifting mode. While thebicycle gear changing apparatus 12 is in the synchro-shifting mode, thegear ratios, which are shaded with diagonal lines in FIG. 4, are notavailable. However, while in the non-synchro-shifting mode, the ridercan shift the first and second gear changing devices 22 and 23 to attainany of the gear ratios in the shift table of FIG. 4. Thenon-synchro-shifting is indicated by the wider arrows. As seen in FIG.4, the synchro-downshift route has a synchro-downshift point that isdifferent from a synchro-upshift point for shifting between the frontchainwheels 47. Thus, the controller 20 sets a synchro-downshift pointof one of the first and third prescribed shift routes and asynchro-upshift point of the other of the first and third prescribedshift routes to provide two distinct synchro-shift routes. In other theembodiment, while the bicycle gear changing apparatus 12 is in thesynchro-shifting mode, the gear ratios, which are shaded with diagonallines in FIG. 4, may be available. For example when the present shiftstage is the 9th stage of the rear stages (CS) and the Top stage of thefront stages (FC) and then the rider operates the downshift switch ofthe other of the first and second shift operating devices 16 and 18(i.e., the one acting as a non-synchro-shift operating device), thefront stage (FC) can be changed from the Top stage to the Mid stage. Atthis point, both the first shift operating device 16 and the secondshift operating device 18 can make an individual shift as in the manualnon-synchro shift mode. When the gear ratio come back to one of the gearratios within the synchro-shift route, the controller 20 then controlsthe shift along the synchro-shift route based on the one of the firstand second shift operating devices 16 and 18 (i.e., the one acting as asynchro-shift operating device).

Thus, the shift table of FIG. 4 defines a plurality of distinctsynchro-shift routes between two adjacent ones of the front chainwheels47. The synchro-downshift point and the synchro-upshift point (e.g., thegear changing points of a synchro-shift) can be set by user by using thecycle computer 24 or an external computer. The controller 20 outputs thecontrol signals to control a gear ratio established by the first gearchanging device 22 and the second gear changing device 23 such that thegear ratio changes in an ascending order during an upshift operation andchanges in a descending order during a downshift operation.

Referring to FIG. 5, with this prestored shift table, when the frontgear changed (i.e., the chain 26 shifted from one of the frontchainwheels 47 to the next one), the rear gear is not changed (i.e., thechain 26 not shifted from the current one of the rear sprockets 46 tothe next one) in a synchro-shift route. However, while the bicycle gearchanging apparatus 12 is in the synchro-shifting mode, the gear ratios,which are shaded with diagonal lines in FIG. 5, are not available. Here,the controller 20 outputs control signals to control only the frontderailleur (e.g., the second gear changing device 23) in response toreceiving the second shift signals from the second shift operatingdevice 18.

As seen in FIG. 6, the controller 20 sets a synchro-downshift point ofone of the first and third prescribed shift routes and a synchro-upshiftpoint of the other of the first and third prescribed shift routes toprovide a single synchro-shift route. Also with this prestored shifttable, in the synchro-shifting mode, if a first shift signal is inputtedafter the gear is shifted by the second shift signal from a gear ratiowithin the prescribed shift route to a gear ratio not included withinthe prescribed shift route (from 1.58 to 1.00), then the controller 20control at least one of the first and second gear changing devices 22and 23 to approach the prescribed shift route. For example, while in thesynchro-shifting mode with the present gear ratio being 1.00 (not withinthe synchro-shift route), when a first (up) shift signal is inputted,the controller 20 operates the first and second gear changing devices 22and 23 to change the gear ratio from the present gear ratio to a highergear ratio that is the closest gear ratio in the synchro-shift route(e.g. 1.19). Also for example, while in the synchro-shifting mode withthe present gear ratio being 1.00 (not within the synchro-shift route),when a first (down) shift signal is inputted, the controller 20 movesthe first gear changing device 22 to change the gear ratio from thepresent gear ratio to the next lower gear ratio (e.g. 0.86). In thisembodiment, in the synchro-shifting mode, when the present gear is outof the synchro-shift route, it is easy to come back the synchro-shiftroute.

While the gear changing apparatus 12 of the above described embodimentis configured such that the synchro-shifting mode and thenon-synchro-shifting mode can be selected by a user as needed and/ordesired, the present invention is not limited to this configuration. Forexample, the gear changing apparatus 12 can have only a synchro-shiftingmode.

In understanding the scope of the present invention, the term“comprising” and its derivatives, as used herein, are intended to beopen ended terms that specify the presence of the stated features,elements, components, groups, integers, and/or steps, but do not excludethe presence of other unstated features, elements, components, groups,integers and/or steps. The foregoing also applies to words havingsimilar meanings such as the terms, “including”, “having” and theirderivatives. Also, the terms “part,” “section,” “portion,” “member” or“element” when used in the singular can have the dual meaning of asingle part or a plurality of parts. As used herein, the term “upshift”refers to a change in a gear ratio of a transmission that results in thebicycle wheels rotating faster per rotation of the crank arms. As usedherein, the term “downshift” refers to a change in a gear ratio of atransmission that results in the bicycle wheels rotating slower perrotation of the crank arms.

While only selected embodiments have been chosen to illustrate thepresent invention, it will be apparent to those skilled in the bicyclefield from this disclosure that various changes and modifications can bemade herein without departing from the scope of the invention as definedin the appended claims. For example, the size, shape, location ororientation of the various components can be changed as needed and/ordesired so long as they do not substantially affect their intendedfunction. Components that are shown directly connected or contactingeach other can have intermediate structures disposed between them unlessspecifically stated otherwise. The functions of one element can beperformed by two, and vice versa unless specifically stated otherwise.The structures and functions of one embodiment can be adopted in anotherembodiment. It is not necessary for all advantages to be present in aparticular embodiment at the same time. Every feature which is uniquefrom the prior art, alone or in combination with other features, alsoshould be considered a separate description of further inventions by theapplicant, including the structural and/or functional concepts embodiedby such feature(s). Thus, the foregoing descriptions of the embodimentsaccording to the present invention are provided for illustration only,and not for the purpose of limiting the invention as defined by theappended claims and their equivalents.

What is claimed is:
 1. A bicycle gear changing apparatus comprising: acontroller including memory with a plurality of pre-stored shift tables,at least one of the pre-stored shift tables comprises a first prescribedsynchro-shift route and a second prescribed synchro-shift route that isdifferent from the first prescribed synchro-shift route, each of thefirst and second prescribed synchro-shift routes having at least onesynchro-shift point; the controller being configured to control ashifting operation of at least one of a first gear changing device and asecond gear changing device based on a selected one of the pre-storedshift tables.
 2. The bicycle gear changing apparatus according to claim1, further comprising a cycle computer operatively coupled to thecontroller to select which one of the pre-stored shift tables is used incontrolling the first and second gear changing devices.
 3. The bicyclegear changing apparatus according to claim 2, wherein the cycle computerincludes an input port configured to be attached to a computer to selectthe pre-stored shift tables.
 4. The bicycle gear changing apparatusaccording to claim 1, further comprising a first shift operating deviceincluding a first electrical switch and a second electrical switch, thecontroller being configured to actuate at least one of the first andsecond gear changing devices in accordance with the first prescribedsynchro-shift route upon receiving a first shift signal generated by thefirst electrical switch of the first shift operating device, and thecontroller being further configured to actuate at least one of the firstand second gear changing devices in accordance with the secondprescribed synchro-shift route upon receiving a second shift signalgenerated by the second electrical switch of the first shift operatingdevice.
 5. The bicycle gear changing apparatus according to claim 4,wherein the controller is configured to operate both the first andsecond gear changing devices at a synchro-shift point of the at leastone synchro-shift point of the first and second prescribed synchro-shiftroutes in response to receiving one of the first and second shiftsignals generated by a corresponding one of the first and secondelectrical switches of the first shift operating device.
 6. The bicyclegear changing apparatus according to claim 4, further comprising asecond shift operating device including a third electrical switch and afourth electrical switch, at least one of the pre-stored shift tablescomprises a third prescribed synchro-shift route and a fourth prescribedsynchro-shift route, the controller being configured to actuate at leastone of the first and second gear changing devices in accordance with thethird prescribed synchro-shift route upon receiving a third shift signalgenerated by the third electrical switch, the controller being furtherconfigured to actuate at least one of the first and second gear changingdevices in accordance with the fourth prescribed synchro-shift routeupon receiving a fourth shift signal generated by the fourth electricalswitch.
 7. The bicycle gear changing apparatus according to claim 6,wherein the controller is configured to operate the first gear changingdevice and the second gear changing device in accordance with the firstprescribed synchro-shift route in response to receiving the first shiftsignal from the first electrical switch, the controller is configured tooperate the first gear changing device and the second gear changingdevice in accordance with the second prescribed synchro-shift route inresponse to receiving the second shift signal from the second electricalswitch, the controller is configured to operate the first gear changingdevice and the second gear changing device in accordance with the thirdprescribed synchro-shift route in response to receiving the third shiftsignal from the third electrical switch, and the controller isconfigured to operate the first gear changing device and the second gearchanging device in accordance with the fourth prescribed synchro-shiftroute in response to receiving the fourth shift signal from the fourthelectrical switch.
 8. The bicycle gear changing apparatus according toclaim 6, wherein the controller is configured to operate both the firstand second gear changing devices at a synchro-shift point of at leastone of the third and fourth prescribed synchro-shift routes in responseto receiving one of the third and fourth shift signals generated by acorresponding one of the third and fourth electrical switches of thesecond shift operating device.